Transmission



Sept. l5, 1931. p, 1 TENNEY 1,823,432

TRANSMISSION Filed May 7, 1923 2 Sheets-Sheet l 5a M 76 4,450 47@ IG P. L. TENN EY TRANSMISSION Sept, l5, 1931.

Filed May 7, 1923 2 Sheets-Sheet 2 Snom/toc www Mew/4f 3&2* lbtomm Patented Sept. 15, 1931 UNITED l. STATES PATENT OFFICE PERRY L. TRNNEY, Or- MUNOIE, INDIANA, AssIGNoR To GENERAL MOTORS CORPORA- 1 TION, or DETROIT, MICHIGAN, A CORPORATION OF DELAWARE TRANSMISSION Appiicatiqn sled may A'2, 1923. seran 110.6373230.

This invention relates to transmissions and is illustrated as embodied in the gear shifting mechanism of a transmission for an automobile.V An object of the invention is to provide inexpensive and readily assembledfgear shifting devices which operate positively-and a compact arrangement of the braking mechanism. i

One important feature of the invention relates to providing gear shifting devices which can be stamped or bent from heavy sheet metal with a minimum of machining, by arranging the sliding gears to be operated by shifter forks, each of which has a vertical operating portion and al slidably supported horizontal portion. In one desir` able arrangement the horizontal portions are supported by a plate which is attached tothe top of the transmission casing along its edges and which may have an opening suitably formed to permit passage ofthe vertical portions y of the shifter forks.

Another feature of the invention relates to an improved interlocking device which is positively operated and which', while not necessarily limited to such use,is especially well adapted to cooperate with the above described ,slidably supported shifter forks. In

the -preferred form, this interlockingv device comprises a member-'which is moved transversely by transverse movement of the gear shifting lever and which has parts operated by such transverse movement to interlock with the idle shifter fork positively to pre. vent it from moving. In the illustrated em-y bodiment of the invention this member is in the form of a slidable plate having a slot embracing the gear shifting lever, and which has a pair of down turned lugs on its opposite sides so arranged that one of themr is' moved by the lever into a notch in the outery edge of the idle shifter fork. y y

From a somewhat different point of view the invention contemplates the provision in a transmission of this type of a simple but highly efiicient arrangement of transmission lock, in combination vwith the gear shifting devices, in such a manner that one shifter fork is locked directly while the other fork is locked indirectly through the medium Of key-controlled lock is arranged so that its bolt can be projected into the registered Openings to lock the mechanism as described.

Other features of the invention relate to al novell mounting for the gear shifting lever, to a protection for the lock by enclosing it in a hardened s teel sleeve, to an eflicient and compact arrangement of a transmission brake, and to othei` novel combinations of parts and desirable particular constructions which will be apparent from the following description of the illustrative embodiment of my invention shown in the accompanying drawings, in which:

Figure 1 is a view partly in longitudinal vertical section and partly in sideelevation showing the improved gear shifting and brake mechanisms in operative relation to the transmission gears; J A

Figure 2 is a section on the line 2-2 of Figure 1 showing some of the parts of the `gear shifting mechanism in horizontal secshowing the arrangement of the key-cong trolled'lock and the transmission brake; and Figure 4 is an exploded perspective view showingr some of the parts of the gear shiftling mechanism. i

In the yform, shown in the drawings the transmission is enclosed in a transmission casing 1() having aclutch housing 12 at one end and in which are arranged in the usual manner, a splined driven shaft 14 which is arranged coaxially of a drive shaft 16, there being a gear 18 on the drive shaft 16 meshing with a gear 20 on a counter shaft 22.

The counter shaft is provided with gears 24 l and the drive shaft 14 is provided with a geary 26' which is axially movable to provide intermediate and high speeds and with a second gear 28 which is axially movable to provide low speed and reverse.

According to the present invention the gears 26 and 28 are controlled by shifter forks 30 and 32, the fork 30 having a verti-l y which is slidably supported by a supporting plate 42 Awhich is turned upwardly at its edges to provide flanges 44 attached to the A top of the transmission casing in any suitable manner as by means of bolts or rivets 46. The horizontal portion of each of the shifter forksis provided with three conical depres-A sions 48 arranged to be engaged by the end of a pin 50 urged toward its lowest` position by a spring 52 (Figure 1),. The pinfor each of theshifter forks cooperates with the depressions to determine the neutral vand two extreme `positions of the fork. As will be apparent from Figures' 2 and 4, the plate 42 is spaced from thetop ofthe transmission 'casing throughout its central portion and the shifter forks are both in neutral position,

and which receive the lower rounded end of a vertically extending gear shifting lever 60 end from the one notch into the other, and.

which can be rocked longitudinally to operate either one of the shifter forks by sliding its horizontal portion along thev central portion of the supporting plate 42. In order to permit such movement of lever 60, it carries a semi-spherical sheet metal ball member 62 which forms a ball-and-socket joint with a conical seat formed in a horizontal web 64 of an upwardly extending portion 66 ofthe cover of the transmission casing 10. Member 62 is held against its seat by a compression spring 68 confined between the semi-spherical member 62 and a Washer 70 slidably engaging the lowersurface of the top of a perforated cap 72, which is secured to the top of portion 66 by means of screws 74` or in any other suitable manner.

i According to an important feature of the .lnvention, there is arranged between the horcentral slot 78 Whichlembraces the lower end of the gear shifting lever in such a manvner that the plate is moved transversely by transverse movement of the lever but is not affected by longitudinal movement of the lever. The plate 76 is also provided with transversely extending slots 79 for the pas-vl sage of the springpressed pins 50. The opposite edges of the interlocking plate havedown-turned lugs 80, vwhich pass through slots 82 formed in the flanges 44 of thesupporting plate, and which are spaced from each other on opposite sides of the interlocking plate 76 at such a idistance that transverse movement of lever 60 operates to move that one of the lugs 8O which is on the side of the interlocking plate toward which the lever is moving out of its interlocking notch 84 (one of which is formed in the outside edge of the horizontal portion of each of the shifter forks) while at the same time the opposite lug 80 is moved into its notch 84 positively to prevent movement of the idle shifter fork. By this arrangement when thelever is rocked' transversely to move it from notch 58 into notch 56 or. vice versa. the active shifter fork will be unlocked b v movement of the lever while thelidle shifter fork will be positively locked by interengagement of its notch 84 with the corresponding lug 80.

The invention also contemplates locking the transmission by a key-controlled lock 86 vof any desired form, which is protected. against tampering by' being housed in a hardened steel sleeve 88, and which has a bolt 90 arranged to be. projected into an opening 92 in the interlocking plate 76 and an opening 94 in the shifter fork32 when these openings register with each other. It will be observed that, before the transmis-- sion can be locked, it is necessary to rock the lever 60 to bring its lower end into thel notch 58, thus moving the interlocking plate 76 in such a manner as to interlock with the shifter fork 30, and at the same time to register the openings 92 and 94. Thus, after the lock has been manipulated to project the bolt 9() downwardly, the shifter' fork 32 is directlyv locked by the bolt, and the shifterlfork 30 is indirectly locked by the bolt through thf.` vmedium of the interlocking plate 76.

At the end of the transmission casing opposite the clutch housing 12 a brake drum 100 is keyed to the driven shaft 14, and is surrounded by a contractable brake `bandV 102 faced with friction material and having bifurcated rends secured to cross pins 104 and 106 carried by bell cra-nk levers 108 pivoted at 100 on a bracket 112 secured to vconnected or bridged at theirvoutcr ends hv a plart (which may be integral with the leve'il if desired) through which passes the lower 4 i Lezaea end of an'operating link 114 connected at its upper end to a rearwardly` extending army of a bell crank lever 116, vwhich may be the usual emergency brake operating lever. The

l invention has been described in detail it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims. f

I claim: y

1. A transmission comprising, in combination, a transmission casing, a supporting plate secured to and spaced from the top of the casing, a pair of shifter forks having portions slidably supported between the plate and thetransmission casing, an interlocking plate between the shifter forks and the casing which is constructed and arranged to prevent movement of both of the shifter forks at once, and an operating lever supported by the casingand arranged to operate the interlocking plate and either of the shifter forks.

2. Al transmission comprising, in combination, a transmission casing, a supporting plate secured' to and spaced from the top of the casing, a pair of shifter forks having portions slidably arranged side/by side on the supporting plate, said portions having notches which are alined with each other when the vforks are in neutral position, an operating'lever arranged to be rocked transversely from the one notch to the other when the forks are in neutral position and to be rocked in another direction to operate either one of the forks, and an interlocking plate operated by transversel movement of the lever to engage the idleV fork to prevent it from moving.

3. A transmission comprising, in combination, a transmission casing, a supporting plate secured to and spaced from the topl of the casing,'a pair ofxshifterforks having operating portions extendingV downwardly through an opening in the plate and having supporting portions slidably resting on the plate, said supporting portions having adjacent notches which are in alinement when the forks are in neutral position and having other notches intheir outer edges, an operating lever arranged to be moved transversely from one of the alined notches into the other for operating either of the `.shifter forks,`and anl interlocking plate having a slot engaging the lever to be mofved by its transverse movement andalso having a pair of down-turned locking lugs on its opposite movedinto the notch in the edge of the idle shifter fork by transverse movement of the 4. .A transmission casing comprising, in comblnatlon, a supporting plate secured to and spaced from the top of the casing, ka pair of shifter` forks slidably supported by the plate, and an operating lever constructedl and arranged to operate either one of the shifter forks. p,

5. A transmission comprising, in combination, a transmission casing, a supporting plate secured to the top of the casing along itsopposite edges and spaced from the casing in its central portion and having an opening in said central portion, and a pair of slidable shifter forks having vertical portions extending through said opening and'having horizontal portions slidably supported between the central portion of the plate and the top of the casing. l

6. A transmission comprising, in combination, a transmission casing, a supporting plate secured to the casing at its opposite edges and spaced downwardly from the casing throughout its central portion and hav- A"ing an opening in said central portion, a

pair of shifter forks each of which has a vertical operating portion extending through said opening and a horizontal supporting portion slidably resting on the central portion of the supporting plate, there being notches in the adjacent edges of the horizontal portions of the shifterl forks which are in alinement with each other when the forks are in neutral position, and an operating lever which is transversely movable to pass from the one notch to the other.

7. A transmission comprising, in combination, a transmission casing, a supporting plate 'which' is U-shaped intransverse cross section to form fianges along opposite edges which are attached to thecasing with the central portion of the plate spaced from the casing, and gear shifting mechanism including parts slidably supported between the central portion of the plate and the top of the casing. f v

' 8. In a transmission device, a housing, gears within said housin forks for shiftlng said gears, said for-s being mounted forlongitudinal sliding movement, each fork 55 edges so arranged that one of the lugs's supporting plate spaced -fi'aogn the top of` thereby for longitudinal movement.

said housing, a pair of gear shifting mem-i bers each formed as a sheet metal plate slidably on said supporting plate and guided 10. The invention defined by claim 9, said .shifting members engaging each other at I their adjacent longitudinal edges, said edges having notches for engagement With thel shifting lever. u

11'. The invention delined by claim 9, said shifting members having notches on their remote longitudinal edges and interlocking means for alternately engaging said notches.

' 12. In a gear shifting device, a sheet-metal supporting plate, sheet 'metal members slidably mounted upon said supporting plate and provided with forks extending through said plate, a sheet metal interlocking plate positioned above said fork carrying members and mounted forv transverse movement only and having means to engage and lock the idle fork.

13. The invention defined by claim 12 said last named means consisting of lugs extending fro'mthefplane of said interlocking plate and positioned to engage one or an# other of said Jfork carrying members.

14. The invention defined by claim 12 said last` named means consisting of lugs projecting downwardly from the remote longitudinal edges of said interlocking plate` and 4engaging notches in said supporting plate whereby said4 interlocking plateis at all times restrained from longitudinal movement7 said lugs-also positioned for engaging one or anotherof said fork members When the other fork is being shifted.

15. The .combination with a transmission housing of a cover therefor, a 4supporting plate secured tothe lower part of said cover, shifting plates slidably supported upon said supporting plate, and each having a lever engaging notch, a fork carried by each shifting plate, and a lever eccentrically mounted with respect to said cover for engaging the notches in said shifter plates.

In testimony whereof I atlix my signature.

PERRY L. TENNEY. 

